Commit | Line | Data |
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b42baaeb JB |
1 | import java.util.ArrayList; |
2 | import java.util.LinkedList; | |
3 | import java.util.ListIterator; | |
4 | import java.util.concurrent.TimeUnit; | |
5 | ||
6 | class Main { | |
7 | ||
8 | private static <E> void addMiddle(ArrayList<E> array, E value) { | |
9 | int mid = array.size() / 2; | |
10 | array.add(mid + 1, value); | |
11 | } | |
12 | ||
13 | private static <E> void addMiddle(LinkedList<E> list, E value) { | |
14 | int mid = list.size() / 2; | |
15 | list.add(mid + 1, value); | |
16 | } | |
17 | ||
18 | /** | |
19 | * Should mimic the collection add(int index, T value) method | |
20 | * @param array [description] | |
21 | * @param value [description] | |
22 | * @return [description] | |
23 | */ | |
24 | private static <E> void addMiddleIter(ArrayList<E> array, E value) { | |
25 | int mid = array.size() / 2; | |
26 | ListIterator<E> iter = array.listIterator(); | |
27 | int i = 0; | |
28 | // go to the element at mid index | |
29 | while (iter.hasNext() && i < mid) { | |
30 | iter.next(); | |
31 | i++; | |
32 | } | |
33 | iter.next(); // Insert before mid + 1 | |
34 | iter.add(value); | |
35 | ||
36 | } | |
37 | ||
38 | /** | |
39 | * Should mimic the collection add(int index, T value) method | |
40 | * @param list [description] | |
41 | * @param value [description] | |
42 | * @return [description] | |
43 | */ | |
44 | private static <E> void addMiddleIter(LinkedList<E> list, E value) { | |
45 | int mid = list.size() / 2; | |
46 | ListIterator<E> iter = list.listIterator(); | |
47 | int i = 0; | |
48 | // go to the element at mid index | |
49 | while (iter.hasNext() && i < mid) { | |
50 | iter.next(); | |
51 | i++; | |
52 | } | |
53 | iter.next(); // Insert before mid + 1 | |
54 | iter.add(value); | |
55 | } | |
56 | ||
57 | private static <E> void addNEMiddle(ArrayList<E> array, int Nelements) { | |
58 | ListIterator<E> iter = array.listIterator(); | |
59 | int i = 0; | |
60 | // go to the element at the middle index | |
61 | while (iter.hasNext() && i < array.size() / 2) { | |
62 | iter.next(); | |
63 | i++; | |
64 | } | |
65 | iter.next(); // Insert before mid + 1 | |
66 | for (int j = 0; j < Nelements; j++) { | |
67 | iter.add((E)new Object()); | |
68 | } | |
69 | } | |
70 | ||
71 | private static <E> void addNEMiddle(LinkedList<E> list, int Nelements) { | |
72 | ListIterator<E> iter = list.listIterator(); | |
73 | int i = 0; | |
74 | // go to the element at the middle index | |
75 | while (iter.hasNext() && i < list.size() / 2) { | |
76 | iter.next(); | |
77 | i++; | |
78 | } | |
79 | iter.next(); // Insert before mid + 1 | |
80 | for (int j = 0; j < Nelements; j++) { | |
81 | iter.add((E)new Object()); | |
82 | } | |
83 | } | |
84 | ||
85 | /** | |
86 | * The main() function | |
87 | * @param String[] args main() function arguments array | |
88 | */ | |
89 | public static void main(String[] args) { | |
90 | ArrayList<Integer> array = new ArrayList<Integer>(); | |
91 | LinkedList<Integer> list = new LinkedList<Integer>(); | |
92 | ||
93 | for (int i = 0; i < 1000000; i++) { | |
94 | array.add(i); | |
95 | list.add(i); | |
96 | } | |
97 | ||
98 | long startTime = System.nanoTime(); | |
99 | //for (int i = 0; i < 100000; i++) { | |
100 | // addMiddleIter(array, i); | |
101 | //} | |
102 | addNEMiddle(array, 100000); | |
103 | long stopTime = System.nanoTime(); | |
104 | long execTime = stopTime - startTime; | |
105 | //System.out.println("Insert time in the middle of the ArrayList: " + TimeUnit.NANOSECONDS.toSeconds(execTime) + " s"); | |
106 | System.out.println("Insert time in the middle of the ArrayList: " + execTime + " ns"); | |
107 | ||
108 | startTime = System.nanoTime(); | |
109 | //for (int i = 0; i < 100000; i++) { | |
110 | // addMiddleIter(list, i); | |
111 | //} | |
112 | addNEMiddle(list, 100000); | |
113 | stopTime = System.nanoTime(); | |
114 | execTime = stopTime - startTime; | |
115 | //System.out.println("Insert time in the middle of the LinkedList: " + TimeUnit.NANOSECONDS.toSeconds(execTime) + " s"); | |
116 | System.out.println("Insert time in the middle of the LinkedList: " + execTime + " ns"); | |
117 | } | |
118 | } |